CBOT said in a statement: “The merger agreement with CME remains in effect. The CBOT and its board has not withdrawn, modified or qualified their respective recommendations that the stockholders vote in favor of the merger agreement with CME and that the members of CBOT vote in favor of certain related matters.”

The special meetings of CBOT stockholders and members to vote on the proposed transaction with CME remain scheduled on April 4.

Jeffrey Sprecher, chairman and chief executive of ICE, said: “We are pleased that the CBOT board has determined that ICE’s proposal is or could reasonably be expected to lead to a superior proposal, which enables CBOT to begin discussions and exchange information with us."

Last week ICE tabled a $9.9bn (€7.4bn) bid for CBOT which offers $1bn more to CBOT shareholders ahead of the vote next month.